# Can a bio-fuel based energy be future houses?

1. May 30, 2014

### dan020350

I was thinking what is the cost efficient and energy efficient way for the new future homes to be.
Since alternative energy like solar and wind is not efficient enough (10%) then I was thinking maybe bio-fuel or algae be the way to be independent from the utlitity companies.

The objective is to make the home free from all expenses, a dream house for the sages.

2. May 30, 2014

### Staff: Mentor

10% efficiency is just fine if the energy source itself is free. For solar and wind, the key consideration is not efficiency, it is the initial capital cost of the installation.

3. May 30, 2014

### UltrafastPED

They used to use "cow patties" for fuel on the Great Plains! Anything that is widely available and cheap will be utilized when the snow flies.

That doesn't necessarily make it the best use.

4. May 30, 2014

### dan020350

I was thinking about the algae farm, rather cow patties but about the solar and is it a solution for the urban community?

5. May 31, 2014

### D H

Staff Emeritus
No. Algae farms require extensive and expert care and feeding. All kinds of things can go wrong. The output from algae farms is algae, not oil. The next step is converting that algae to "algae crude". This requires a different kind of extensive and expert care and feeding, and the process also involves some rather nasty chemicals as inputs and produces some rather nasty chemicals as byproducts. All kinds of things can go wrong. Converting that to algae crude to a usable product requires yet another king of extensive and expert care and feeding.

If you have a big inheritance begging to be wasted plus PhDs in biology, chemistry, mechanical engineering, and petroleum engineering, then yes, a DIY algae farm that ultimately produces usable fuel is a real possibility.

I am not disparaging the concept of biofuels from algae per se. I am disparaging the notion of a backyard DIY project. There are huge economies of scale at play here, and a wide range of technical expertise is needed to make such ventures successful.

6. May 31, 2014

### Ivan Seeking

Staff Emeritus
Perhaps the easiest way to understand the challenge is to consider the economic potential per square foot, and compare this to any reasonable estimate of operating costs. If we assume the very generous case of 4000 gallons of fuel net [after production energy losses] per acre-year, then we might expect a user value of around $16000 per acre-year of algae. With 43,560 square feet per acre, we net about 37 cents per square foot per year. Try to build, operate, and maintain a bioreactor or even a raceway for that price. The energy required for aeration alone can kill the budget. 7. Jun 1, 2014 ### NascentOxygen ### Staff: Mentor There was a ripple of excitement in some circles a few years back with the discovery of an alga whose byproduct of photosynthesis is H2 gas. Things seem to have gone quiet, though; maybe it didn't live up to its promise? 8. Jun 1, 2014 ### Ivan Seeking Staff Emeritus Hydrogen from algae is a more distant goal. Though there is an effort in Spain to produce methane from algae that seems most promising. Their approach allows the use of fast-growing strains of algae not suitable for oil production. https://www.physicsforums.com/showpost.php?p=4557502&postcount=534 There is work to improve the efficiency of algae for hydrogen production. http://www.nrel.gov/news/press/2014/8301.html [Broken] http://www.sciencedaily.com/releases/2013/04/130415182430.htm Last edited by a moderator: May 6, 2017 9. Jun 1, 2014 ### dan020350 Everyone provide good information, but we will eventually make a decision. What is your decision of obtaining the goal? 10. Jun 1, 2014 ### Ivan Seeking Staff Emeritus The market will make the decision based on price. If [and I believe when] algal fuels are competitive at the pump, you will be using algae-derived fuels. 11. Jun 1, 2014 ### Ivan Seeking Staff Emeritus Origin Oil is becoming a major player and claims to be nearing a competitive price for algae oil. https://www.youtube.com/watch?v=tzWvl9WDBnw We will just have to wait and see if they can produce as claimed. 12. Jun 1, 2014 ### anorlunda Use steam from boilers fueled by wood. You could so almost anything with the steam engines -- heat, cool, generate electricity. Wood isn't free, but it is inexpensive. If you measure efficiency in terms of acres of land and labor needed, most bio fuels would have a hard time beating wood. Warning: wood fired boilers have been banned in many places because the emit so many pollutants; but that wasn't part of your question. 13. Jun 3, 2014 ### Ivan Seeking Staff Emeritus It would be impossible to power the country on wood. It is only an option right now because very few people depend on wood for power - there is very little demand. How long does it take to replace a forest? Algae can double in mass as often as every few hours, though most good oil producing strains may only double in mass once every day or two. How long does it take a tree to double in mass? I had five acres with about two acres of large trees, and we couldn't grow trees fast enough to use all wood heat [just space heat]. Had we tried, eventually all two acres of trees would have been gone. 14. Jun 3, 2014 ### dan020350 Exactly 15. Jun 6, 2014 ### OmCheeto hmmm... So If I were to build a 500 ft2 algae eve around my house, I could expect to get 40 gallons a year? Seems adequate. Jay Leno consumed only 4.65 gallons of gas in his Volt over the course of a year. I suppose if he had solar panels on his roof, that would provide his primary source of energy. (ref) Meshing the infrastructure technologies of electrical(two-way) transmission, and natural gas(one way) delivery, I don't see much of a technological barrier to creating a community wide algae transport system. Kind of like the sewer system, only a green algae slurry, flowing to a central processing facility. Economies of scale, of course. You wouldn't want everyone to buy a bio-reactor. The 35 extra gallons of fuel produced from each home could be sold to fuel semi-trucks, and ships, and reprocessed into jet fuel. So if we put this 500 ft2 eve on all 70,000,000 single family dwellings (ref), that would generate about 2.5 billion gallons of excess fuel a year, assuming we all drove Volt type cars. Eeek! Airline fuel consumption for 2013: 10 billion gallons. (ref) It's best to do the math, before implementing some of my ideas. I have 1/6 acre, and cut down two trees, twenty years ago. I just used the last of it. Put a sweater on! :tongue: Though I did only burn fires on the weekend, and used electric heat on the weekdays. :yuck: 16. Jun 6, 2014 ### D H Staff Emeritus Most likely you'll get a festering, stinking pond of yuck with zero economic value. This will result in tons of complaints from your neighbors to your municipality about the unsightly, stinky, and disease-ridden mess in your backyard. Algae normally does not produce fatty acids and lipids. You need to feed it just right, stuffing it with some nutrients but seriously starving it of others to make that algae capable of producing oils. Do that just right and now you have a new problem: The algae is susceptible to all kinds of problems because you have intentionally stressed it to near death. You need a PhD in biochemistry to successfully manage your backyard algae pond. Suppose you do manage to keep your backyard algae pond on track and can regularly skim oil-laden algae from your pond. You now have to separate the water, chlorophyll, and other stuff from the oils. You need a backyard centrifuge to squeeze the oils out of the scum you drained off your pond. If you have a dual PhD in biochemistry and mechanical engineering you might have the wherewithal to accomplish the first task and the second. Do this just right and you'll have green sweet light crude. Pour a gallon of sweet light crude in your car and you'll have a car that no longer works. You need a backyard refinery to convert that green sweet light crude into usable fractions. That means a third PhD, this time in chemical engineering, and that means even more complaints from your neighbors. The way to overcome the first two problems is to make the project much bigger than a backyard DIY algae farm. Now economies of scale can kick in. The way to overcome the third problem is to sell the green sweet light crude to a refiner. The only remaining obstacle is to somehow make a profit on those sales. That turns out to be the biggest problem of all. 17. Jun 6, 2014 ### dan020350 What are the mechcanic and logistics from algae to oil? 18. Jun 7, 2014 ### OmCheeto Actually, my design is based on the carport I built several years ago. I purchased clear poly-carbonate sheeting, as it's already dim here, and my house was surrounded by 100 foot tall Douglas Fir trees. Even their branches can kill you, if they snap off. My idea was to double up the sheets, creating a closed channel system. ps. Live algae doesn't stink. Dead algae stinks. I don't have a degree in anything, and I have no delusions of doing such a project on my own. This is why I alluded to creating a secondary sewage type system. Algae is harvested and flushed to a core facility with all the gadgetry: centrifuges, refineries, etc. etc. The only gadgetry required at the home would be the liquid filled house eave, a water pump, a gas pump, a filter, and a flush valve. Well, the only reason Jay Leno used any gas at all, from my recollection, was because the gas will get stale after awhile. My carport cost about$1 per square foot, and is ≈200 ft2

Though that was ≈20 years ago when I originally installed it.

It looks as though the price has doubled, so I'm guessing $2/ft2*500 ft2=$1000

With production at 40 gallons per year, and diesel @ $4/gallon, that's$160/year, which yields a return on investment of 6.25 years.

Since most homes come with eaves in the first place, it might be sooner. But since I've not calculated in all the cost, it would probably be longer.

But, IMHO, doing something expensive, is better than doing nothing at all, and continue to watch \$400,000,000,000 per year being drained from our economy, which is what Stephen Chu said was the cost of imported crude oil, when he came to visit my former employer awhile back.

Ah ha!
hmmm... I have this weird suspicion that I'm repeating myself...

19. Jun 7, 2014

### OmCheeto

I just discovered that Oregon couldn't even power Oregon with our wood, even though we are ranked 39 in population density. (based on some wild estimates)

5,000,000,000 annual sustainable harvest of Oregon trees in board feet (ref)

~46 megajoules/kg of Gasoline (petrol) / Diesel / Fuel oil
16.2 megajoules/kg of wood
(ref)

29,201,748,097,500 watt hours of sustainable Oregon forest(annual)
46,800,000,000,000 Goonie* watt hours/yr consumption(based on my electrical usage and number of fellow Goonies)

And that's at 100% efficiency. I seriously doubt my old Franklin stove has an efficiency over 0.1%. :yuck:

I estimate my two trees were between 50 and 75 years of age. Interpolating a 7 day/week vs 2 day/week burn cycle, I would have burned all my wood in less than 6 years. Hardly sustainable.

I wonder how long it would have lasted, with modern technology

bolding mine

I didn't see any quoted efficiency numbers. Though I've seen numbers quoted for natural gas units in the mid 90's.

hmmm... I wonder what would happen if we utilized the CO2 from wood stoves to feed our algae eaves? The hundred or so trees, on my 1/6 acre lot, do grow vertically.

hmmm......

Didn't a 12 year old design a 3 dimensional solar panel awhile back?

Yup
Have I ever mentioned the fact, that I love being surrounded by smart people?

*Goonie: self-depricating term used by persons from Oregon when referring to each other. Portmanteau of Goon(generally a bad thing) and Oregon(nice place to live). See also: Orygoonian.

20. Jun 7, 2014

### dan020350

Prays* for more wisdom